The Blade Pitch Control Of Direct Drive Wind Turbine Based On Fuzzy Logic

As clean,renewable and huge reserves of energy,Wind energy is one of the important means to deal with the current energy cris is and environmental pollution.Its development has been the focus of the countries all over the world.At present,the large variable speed variable pitch wind turbine gradually replace fixed pitc h wind turbine,and has dominated the market.Hence the research,development and application of the advanced control system have important theory value and practical significance.First of all,this paper studied the aerodynamics of the variable pitch win d turbine,and got the theoretical basis of the control of the variable pitch variable-speed constant frequency,and discussed the basic rules of the blade pitch control of the wind turbine.This paper expounded the requirements of the blade pitch control system,studied the structure and the basic control strategy of the electric pitch control system.Then discussed the basic principle of direct torque control of permanent magnet synchronous motor,and designed the three closed-loop control scheme with torque,speed and position of electric pitch servo system based on direct torque control.Due to the wind power system is nonlinear and difficult to establish accurate mathematical model,the biggest advantage of fuzzy control is that it mainly relies on the expert's experience or knowledge,does not depends on the precise mathematical model of the object.Therefore,this paper based on fuzzy logic control method,designed the fuzzy PD position loop controller and fuzzy PI speed loop controller for the electric pitch servo system.Then,based on the three closed loop control scheme and the method of direct torque control method,built the mathematical model of the blade pitch servo system,and conducted a simulation research.Through the simulation,it is verified that the designed system has a good performance.At last,based on the principle and its control strategy of variable speed constant frequency wind power generation system,make use of Matlab/Simulink,then build the direct drive wind power system model.Based on the parameter self-turning fuzzy control method,this paper designed the variable blade pitch controller,combined with the electric pitch servo system model mentioned above,a simulation was carried out,and got the output power and the pitch curve of wind turbine generator above the rated wind speed.It can be seen from the simulation results: the blade pitch control system can meet the demands of stable power control at high wind speed conditions very well,has a good dynamic performance and high reliability.